1. Field of the Invention
The present invention relates to a colorimetric device which measures color data used so that a subject field is photographed with appropriate color balance.
2. Description of the Related Art
In order to photograph a subject field with an appropriate color balance, there are cases in which color filters are loaded onto a camera for corrective use. Heretofore, a photographer using a colorimetric device in order to select an appropriate color balance, performed photometry of the balance of an incident light (red, blue, green), a color temperature of the subject field, a light balancing factor (LB value), and a color compensating factor (CC value). Furthermore, on obtaining color data for the proposed filter, corresponding to this light balancing factor and color compensating factor, a predetermined color filter is selected based upon the color data.
However, the color temperature and light balancing factor, among the color components incident from the subject field, were calculated using the photometric values of the red and blue color components, while the color compensating factor was calculated using the photometric values of the red, green and blue color components.
Moreover, when the photometric value of the green color component was less than a predetermined standard value, prior colorimetric devices determined that accurate color data could not be calculated, and that the photometric value did not have reliability, and performed a display to this effect, warning the photographer. Such technology was disclosed in, for example, Japanese Patent Publication No. JP 5-53218.
Nevertheless, in the above manner, the prior colorimetric devices, because they calculated the color temperature and color balancing factor using the photometric values of the red color component and the blue color component, have the problem that when the photometric value of the green color component is above the standard value, the color temperature and color balancing factor were calculated as being reliable and were displayed, even in the case where one of the red and blue color components was insufficient. These calculations occurred in spite of the fact that there was in fact no reliability.